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It used to be at avhistory.org but they have moved totally to CFS3. I've attached Machine Guns & Cannons.zip which has the 1% spreadsheet that I downloaded years ago. The setting at the end of the Gunstation line should be the weight of 1 round and 1 link. The airfile places this at the co-ordinates given in the middle of the Gunstation line. The Guns line provides the details about where the projectile leaves the plane (and where the flash appears) as well as the trajectory. A P40 site at http://staff.jccc.net/droberts/p40/p40a.html

That was exactly the spreadsheet I was looking for. I had a copy way back but don't remember where it was stashed. The copy you sent pretty much confirms what I remember: THIS spreadsheet also uses bullet rather than round weight.

The US 30 caliber MG has a Bullet and Link weight of 0.343 ounce. This works out to 150.0625 GRAINS which is the approximate weight of the bullet only. A .30 M2 Ball round is 150 to 152 grains. Armour Piercing .30-06 bullets weigh roughly 170 grains.

For those who don't understand the point of the discussion: When loading ammunition for one of the .30 Caliber Wing Guns for the P-40, the 490 cartridges with bullets, case, powder and the little steel links holding them all together should weigh about 26 pounds.

In CFS, we only load the bullets that will be shot. Case, Powder, and Link are omitted. The weight of 490 bullets only is about 10.50 pounds.

Hey Hubbabubba,
I take it that this will seriously affect the loadout of your Killer Jeep?

May I kindly suggest that this line of posts should be worthy of its own thread?

Hey Hubbabubba,
I take it that this will seriously affect the loadout of your Killer Jeep?

Not really, the MG jeep only has 600 rounds and the load is carried at CoG so that it causes no parallax distortion in TG2. And the vehicle being already released, I have no intention to put the toothpaste back in the tube. I will certainly experiment on this for future releases though.

Could it be that the projectile weight has some influence on the ballistic trajectory? Penetration into "DP boxes"? Inertia? I'm thinking out loud here...

I found that page also at Simviation. Try the download. It doesn't work. I believe it is the same file as you had in your earlier link.

I don't believe the weight of the projectile should really mean anything. The hitting power is determined by a multiplier. I don't believe the trajectory can be determined by projectile weight. Ballistic Coefficient (Drag) is a more important factor.

Knowing what we know now, what do you all believe would be the best idea? Round and Link weight or keep it as Projectile weight? It seems to me that this would also be a good time to also rationalise damage values and hit boxes. What I and others have noticed is that the hitting power of CFS weaponry is much worse than history would indicate.

IIRC, The consensus at the old 714th was that damage was about 1/3 what it really should be.

As an example, The typical heavy bomber (B-17) could be brought down with an average of about 15 hits (anyone remember the actual number?) of 20 mm cannon and average only THREE hits of 30 mm cannon such as the MK 108. The typical 20 mm cannon in CFS has 1D1 x 24 hit points and the 30 mm has 1D1 x 89 hit points. Just about every system on a plane has at least 100 hit points. That means that a single hit by a 30 mm can't destroy any system. In reality, a single hit in the right place could blow off an entire wing. A fuselage hit would blow a hole about 3 feet in diameter and rip up all the structure under the skin.

Dave spreadsheet says "Bullet & Link wt". So, people would have taken the time to take into account the weight of the link, which should not be more than a fraction of an ounce, but would have overseen the weight of the case and propellant? Bizarre...

On this site, the M2 AP .50 cal cartridge is weighting 1,248 gr (2.852571 oz) and the projectile 706.7 gr (1.615314 oz); more than 43% of the "discarded" weight would have been omitted?

So, my answer to "Round and Link weight or keep it as Projectile weight?" would be "round and link", as long as the case is discarded. I'm not sure, but I think that some German cannons would keep the case like in a giant revolver.

As for DP-boxes vs Damage point, what do you think; should it causes more or less damage? I've seen opinions that differ from yours and, in the case of the stock .303, they would have reduced the points "shaved" from a box.

In multiplayer games, bombers are dropping in a pretty decent manner when hit. The jeep gas tank will go BOOM with 4 .50 caliber bullets, and should probably go at two. But in QC, a one pass strafing by a P-47D does the job 99% of the time.

BTW- I think that the "weight question" should be asked at the CFS2 forum.

I am not a member out at Flightsim. Actually I probably AM a member but can't remember the login or password.

Here is the "Weight Issue" as I see it. Most fighters eject the spent case and link. Some do not. I believe the 37 mm cannon on a P-39 does not. Typical swivel guns do not toss the spent cases overboard. They end up on the floor of the aircraft. In this case (no pun intended), the weight of the ammunition should be taken into account when the aircraft is loaded. It is carrying the extra weight at Take-Off. The weight is not reduced when the ammunition is spent. I don't know we can do about that in CFS. I say that we should put in the full weight of the rounds and links so that ammunition loads are a distinct weight factor in performance. I go to a fair amount of effort to calculate the Basic Weight plus pilot.

BTW, Why are German pilots heavier than US Pilots by 20 pounds??? US Pilot weights are 200 pounds. German pilots are 220 pounds (100 Kilograms).

With US fighters, often there is a selection of load conditions: Fighter, Fighter Bomber, and Fighter Overload. Funny thing, but as a "Fighter", the aircraft typically won't be carrying a full ammunition load or full internal fuel load. Fighter Overload has both at maximum.

Also, I am not sure where you got the numbers for a .50 caliber round. The full round and link weight which I got from the P-50C loadout was 760 rounds == 228 pounds. That works out to 4.8 ounces per round.

Regarding the damage from a .303, I really don't know. I believe they are too potent in the game. Some of the cannons like the 20 mm MG 151/20 and 30 mm MK 108 are not potent enough. The statistics I quoted were gathered by the Luftwaffe. If the AVERAGE number of hits needed to kill a B-17 is only 3 rounds, there were plenty of cases it took fewer. Check out wartime photographs for confirmation.

I make no claims about a .50 caliber because I haven't done the research, but I would make an assumption that a single MK 108 hit should blow up the Jeep's fuel tank, right?

When flying against AI bombers, you would think you are flying against B-40s. Their gunnery is intense and extremely accurate. A single pass doesn't tend to kill all that often in my experience though perhaps I don't shoot very well. The following is yet another diversion from the topic, but I believe the bomber DP files should have reduced range for AI gunnery. You can't much alter their accuracy, but a fellow with a ring and bead sight or just a ring sight (often USAAF swivel guns didn't have a front sight), isn't terribly accurate at any range and certainly not past about 200 yards and certainly not to a thousand yards.

I am not a member out at Flightsim. Actually I probably AM a member but can't remember the login or password.

The files are in the mail.

Here is the "Weight Issue" as I see it. Most fighters eject the spent case and link. Some do not. I believe the 37 mm cannon on a P-39 does not. Typical swivel guns do not toss the spent cases overboard. They end up on the floor of the aircraft. In this case (no pun intended), the weight of the ammunition should be taken into account when the aircraft is loaded. It is carrying the extra weight at Take-Off. The weight is not reduced when the ammunition is spent. I don't know we can do about that in CFS. I say that we should put in the full weight of the rounds and links so that ammunition loads are a distinct weight factor in performance. I go to a fair amount of effort to calculate the Basic Weight plus pilot.

I think that the AIR file should represent the aircraft weight minus fuel and ammo. Depending on the information we have, it may be a difficult task. We have to assume, in absence of information to the contrary, that "maximum load" means full tanks and full ammo. Ammo should be deduced by subtracting the weight of "spent" ammo. For ejected links and cases, then the hole cartridge and the link should be taken into account while, in the case of self-contained clips, drums, or guns on a swivel, only the projectile and the propellant should count.

This means that, for example, a B-17 without any ammo will have to take off with its floor littered with empty cases but, quite frankly, who leaves ground with an unarmed flying fortress?

BTW, Why are German pilots heavier than US Pilots by 20 pounds??? US Pilot weights are 200 pounds. German pilots are 220 pounds (100 Kilograms).

No idea. Must be a bit of census average mixed with a round number to simplify calculations.

With US fighters, often there is a selection of load conditions: Fighter, Fighter Bomber, and Fighter Overload. Funny thing, but as a "Fighter", the aircraft typically won't be carrying a full ammunition load or full internal fuel load. Fighter Overload has both at maximum.

As if "maximum load" was not fuzzy enough! LOL!

Also, I am not sure where you got the numbers for a .50 caliber round. The full round and link weight which I got from the P-50C loadout was 760 rounds == 228 pounds. That works out to 4.8 ounces per round.

The link was in the post. The "ounce translation" was done with a little app I have, as the site gives the weight in grains or grams. Here are some weight as they appear; M1 tracer - 1,785 gr or 4.08 oz, M2 ball - 1,813 gr or 4.144 oz, M2 AP - 1,812 gr or 4.141714 oz, M8 API - 1,764 gr or 4.032 oz, M10 tracer - 1,752 gr or 4.004571 oz, M20 API-T - 1,718 gr or 3.926857 oz... the list goes on. Some projectiles weigh are also given, but not for all types. I think that, with the addition of the link, we are in the same ballpark.

I also made an error in my calculations; the cartridge minus the projectile weight more than the projectile. The M2 AP weight is 1,812 gr, not 1,248. My mistake.

Regarding the damage from a .303, I really don't know. I believe they are too potent in the game. Some of the cannons like the 20 mm MG 151/20 and 30 mm MK 108 are not potent enough. The statistics I quoted were gathered by the Luftwaffe. If the AVERAGE number of hits needed to kill a B-17 is only 3 rounds, there were plenty of cases it took fewer. Check out wartime photographs for confirmation.

I think we should look more into normalizing DP boxes than damage points system. The latter was thought about pretty deep while damage caused is basically left to "artistic license".

I make no claims about a .50 caliber because I haven't done the research, but I would make an assumption that a single MK 108 hit should blow up the Jeep's fuel tank, right?

Right. According to ARMS_WW2.dat, the Rheinmetall-Borsig MK 108 has a "1d1*73" dice-point ratio, the jeep fuel tank goes boom at 50 points.

When flying against AI bombers, you would think you are flying against B-40s. Their gunnery is intense and extremely accurate. A single pass doesn't tend to kill all that often in my experience though perhaps I don't shoot very well. The following is yet another diversion from the topic, but I believe the bomber DP files should have reduced range for AI gunnery. You can't much alter their accuracy, but a fellow with a ring and bead sight or just a ring sight (often USAAF swivel guns didn't have a front sight), isn't terribly accurate at any range and certainly not past about 200 yards and certainly not to a thousand yards.

I don't want to boast (yes, I do!!!), but I once downed 8 B-17 in the "Fat cars" scenario without using rockets. Granted, my Fw90 was a flying colander when I made an emergency landing at Guyancourt, but it is feasible if you know where to shoot. Next time, try the tip of the wings, or at least the portion between the tip and the exterior engines (#1 or 4). For some reason, they do explode more often than they should and, when they don't, they have a tendency to collide with their neighbors in the formation.

Yes, bombers gunners are all sharpshooters, Bf 110 included. But in QC, they tend to be more "human". Dropping distance at 183 meters would make missions look weird; gunners were shooting as soon as they "thought" they had a chance, hoping that the hail of bullets would make the attackers think twice before getting closer and, at least, would diminish the precision of their attacks. Le May's raids over Japan with unarmed B-29 showed no more casualties due to fighters' interception than "normal" raids, which says a lot about air gunnery.

We could diminish the accuracy for AI (humans do the job all by themselves...) by tweaking the "dice factor" from, let's say, "1d1*" to "1d4*". This would cut the hits by 75% while keeping the hail of bullets coming. Call me masochist, but I like the audio-visual effect.

I like the idea of different bullet weights depending on fighters or bombers. I have been working on the assumption that the bullet weight at the end of the line was round and link for many years! The 1% people also worked on more realistic DP boxes and I attach their notes (unfortunately without pictures but the full research might be found at avhistory.org. I had an idea of fixing all my dp files to be like this but it is yet another project that never got started! For accurate AI gunners I have amended my dp files so that they open fire at 300. That is normally the maximum range in which I engage them when in my fighter so it makes it all a lot fairer. For the damage that a round does, the speed and weight does appear to matter, only the 1d1x73 allocates the number of damage points. The speed of the bullet affects the trajectory I believe in CFS but I have not done any trials to prove this. I believed the 1% people when they said that small calibre guns were overpowerful and big cannon were underpowered; I adjusted my damage dice to the figure in their spreadsheet and Spitfires and Hurricanes now shred the enemy but it is much more difficult to shoot down lots of planes. The .5" power seemed about right but 20mm and 30mm cannon become very effective when their damage is increased.

Got your email. Also found the registration for Flightsim.com in my email as well.

I believe I would prefer having the guns on a Bomber dispose of entire round and link as far as weight is concerned. Yes, it would be somewhat inaccurate with the real bomber more or less carrying the extra links and cases around, but those could also be disposed of. Consider that a multi engine bomber in trouble often disposes of guns as well other items that can be unbolted. We can't do that in CFS, so at least give a disabled bomber the best break that we can. Also, the ammunition load may vary according to fuel and bomb loads.

Regarding aircraft weights, Here is the issue as I understand it:
Empty Weight (Not hard to find): Basic airframe and engine. Does not include guns, armour, radios, equipment or consumables. Not generally useful except as a starting point.

Basic Weight (Nearly impossible to find but generally the most useful): Airframe, engine, all equipment, trapped fluids. No engine oil which is considered a consumable, fuel, ammunition or pilot. I add the weight of the pilot and oil which I declare NOT to be a consumable and enter into .AIR file.

For the P-40C, I have LOTS of information. I can email it to you, but it is just under a 3 MB pdf.

If I don't have the information, I estimate from the known data and weight of equipment. Most of the time, my estimates are within 50-150 pounds of the actual values when I have found the actual data later.

I don't really believe damage boxes or damaged caused should be left to artistic license. Consider the case of a gunstation with a single gun. Just about ANY hit will disable that gun. Why should it have 150 points? The heaviest stock gun (30 mm MK 108) only causes 1d1x89 points of damage. We need TWO hits to disable a gun while in reality a single .30 caliber hit stands a very good chance of destruction???

Aiming at a wing to best destroy a bomber doesn't match with reality. This IS supposed to be a simulation.

With LeMay and his B-29s, their cruising altitude was about 10,000 feet higher than the B-17 in Europe. Most of the Japanese fighters couldn't even reach them until they stopped bombing from the Jetstream. 35,000 feet was above the service ceiling of most J Fighters. No wonder that guns or no guns made little difference. Also the top speed of the B-29 (360 mph) was very near the top speed of the best J Fighters and even faster than some of them. Consider also that a bomber after its bomb run would tend to leave the target in a slight dive and be quite a lot faster than the typical interceptor. B-17s in Europe would come over the target at 25,000 feet and below at just a bit over 200 mph.

how about a Mosquito MK IV or VI
that can make it to Berlin and back?
there are several nice models out there,
most based on P.H.F. Burnage's excellent design,
but none have a range of 1,000+ miles.
I was able to get 975,
but that was at 50% throttle
and maintaining 5000 ft
with no bomb load and no weather.

okay, late yesterday, I was able to wring out the Mk VI FB
and got 1097 miles at 239 mph.
this is still a far cry from the 1850 mile range
specified for the Mk VI fighter bomber.
and then, there's the Mk IV bomber variant
which had a specified 2040 mile max range
humph

The FB6 type pilot manual states that the aircraft had 10 standard tanks! The "outer-wing" tanks (2 per wing) had 116 gallons capacity. The "main inner-wing" (2 per wing) had 286 gallons. The "main fuselage" two tanks carried 50 more gallons for a total of 452 gallons. These were "Imperial gallons", in US gallons, it was almost 543.

An additional "long range" fuselage tank could carry 63 gallons and two dropable 100 gallons wings tanks gave the total of 715 Imperial gallons (858.6796 US).

In some types, fuselage capacity was increased to 63 gallons and dropable 200 gallons tanks were also used.

P.S.- When I was referring to LeMay's bomb runs, it was the "torching" night raids made at ±10,000 feet. Night interception was difficult for the Japanese but, when they could manage such interceptions, downing B-29 was not easier. The best defense for the bombers was evasive maneuvers, sometimes dropping at tree-top level while returning to sea.

In conversations with my neighbour who flew B-26 Marauders (and confirmed by other sources), the bombers would typically leave the target in a shallow dive and be going much faster than their maximum level speed. Considering these B-29s were flying night raids, the interceptors would have been twin engine night fighters. I don't know what the low altitude speed was for the B-29, but I don't believe the Japanese had a night fighter that was substantially faster in level speed than a B-29 at ANY altitude.

Here's a status update on the P-40C:

Engine power is about 20 hp more than it should be at most altitudes, but the sources I have do not agree completely, so this is more or less reasonable.

I found that the P-40C although it was just a touch (about 5 mph) faster than it should be at various altitudes was flying distinctly nose down. I adjusted the angle of incidence of the wing (Record 1204) to zero degrees which helped. The plane was then MUCH slower. The angle for minimum drag was also adjusted as was the coefficient of drag to bring the speeds back to what they were before.

The P-40C has much less engine power than the P-51D I typically use as the basis for flight models. Last night, I checked out the propeller power coefficients of all the stock flyable aircraft on the assumption that Record 512 to adjust propeller pitch would correspond to the power coefficient of the aircraft. Testing was done at an altitude of 500 feet.

I found that the closest match in power coefficient to the P-40C was the stock P-47D Thunderbolt. My suppliers quickly obtained a P-47D propeller which was cut down and mounted to the P-40C. The maximum speed was reduced very slightly (about 2-3 mph) as compared to the P-51D propeller, but hopefully the pitch changes are more reasonable.

As for the Mosquito; East-Anglia to Berlin is ±540 miles. 1,080 miles is well within "Woody Wonder" specs. B Mk IV and, later, Mk XI, would carry 4,000lbs "cookies" to that city, sometimes twice in the same night!

I went "bingo" once in a MP bomb run at St-Leu d'Esserent, flying as pathfinder in a Mosquito... a mere 153 miles, what a pity...

Regarding performance, especially maximum level speeds, I actually prefer my numbers to be slightly higher (5-10 mph faster) than the recorded values because my testing method is to use autopilot and this is much more precise than actual human pilots can hold. In other words, the real aircraft probably went faster than the records show.

Regarding performance, especially maximum level speeds, I actually prefer my numbers to be slightly higher (5-10 mph faster) than the recorded values because my testing method is to use autopilot and this is much more precise than actual human pilots can hold. In other words, the real aircraft probably went faster than the records show.

- Ivan.[/QUOTE]

There were so many thing that would affect the performance of a used aircraft, didn't Dowding admit that his Hurricanes were pushed to get 300mph.
Dents, battle damage repairs, worn and flaking paintwork indeed even the paint type itself would knock off speed and endurance. Maladjusted control surfaces, empty bomb cradles added even more. Also not every engine fitter in the RAF was Halton trained so engine performance would and did vary as did the fuel consumption between a new engine and a well used engine.
To get within the 1% mark is an exceptional acheivement but there were those examples that couldn't get within the recommended performance due to the previously mentioned cicumstances.

You are describing war-weary operational aircraft. All of mine are fresh from the factory, best examples of their type, and perfectly maintained.
:salute:

The biggest discrepancies in performance between aircraft in the field and factory fresh tend to be with Japanese aircraft. As an example, an aircraft engine would be designed for 2000 HP. The errors in manufacturing, poor materials, a supercharger that doesn't work as well as it should, and poor maintenance in the field might bring the actual output down to 1400 HP.

I believe this is fair. Even American aircraft in the continental US had problems like these. Check out the planes that flew against Koga's Zero that was captured in the Aleutians. A few of them could not function well enough to be representative of the types for performance comparisons.

For what it's worth, I am not really aiming for 1% accuracy for the reasons stated above. Some of the settings are not granular enough: Any change creates more than 1% in performance. To offset these, other settings need to be skewed. Also, CFS doesn't represent multi-speed superchargers. I would much rather have the performance curve be a best match across the altitude range rather than exactly match one or two heights and be way off at other parts.

personally, I prefer my steak grilled,
slightly charred and rare inside.
actually, a well wrapped roast
placed in the engine compartment
would be just about right
after a several hundred mile road trip.
potatoes, carrots and such
added with a hundred or so to go.
mmm, mmmm, mmm

I have added N50* E/W0* to my GPS
which will be the start point
set AP heading 270,
throttle 60% for starters
AP IAS hold does not work
slow, easy 300 FPM climb
and then, cruise until out of fuel.
there, I will take the GPS distance reading
back to N50* E/W0*
the question being is the GPS measuring
in statute miles or nautical miles?

the flight will be made in multi player
so the pause mode will have no effect.